stackrc is the primary configuration file for DevStack. It contains
all of the settings that control the services started and the
repositories used to download the source for those services. stackrc
sources the localrc section of local.conf to perform the default
overrides.

DATABASE_TYPE

Select the database backend to use. The default is mysql,
postgresql is also available.

Other services that are not enabled by default can be enabled in
localrc. For example, to add Swift, use the following service
names:

enable_service s-proxy s-object s-container s-account

A service can similarly be disabled:

disable_service horizon

Service Repos

The Git repositories used to check out the source for each service
are controlled by a pair of variables set for each service.
*_REPO points to the repository and *_BRANCH selects which
branch to check out. These may be overridden in local.conf to
pull source from a different repo for testing, such as a Gerrit
branch proposal. GIT_BASE points to the primary repository
server.

NOVA_REPO=$GIT_BASE/openstack/nova.git
NOVA_BRANCH=master

To pull a branch directly from Gerrit, get the repo and branch from
the Gerrit review page: